Wire-rod and the like hot-rolling machine

ABSTRACT

Wire-rod hot-rolling machine ( 1 ) which comprises a plurality of roller-provided rolling units ( 2 ) which are arranged one after the other along the wire-rod feeding paths (p); the roller-provided rolling unit ( 2 ) being formed by a plurality of rolling-mills assemblies ( 3 ) each of which is provided with a pair of opposite, counter-rotating rolling mill rollers ( 4 ), which are arranged parallel and adjacent each other; said rolling-mills assemblies ( 3 ) being arranged one beside the other, coplanar to a corresponding reference plane locally perpendicular to the feeding paths (p), each at the feeding path (p) of a respective wire rod (b), and are oriented so that the rotation axes (R) of the rolling mill rollers ( 4 ) of the various rolling-mills assemblies ( 3 ) are locally parallel to one another while intersecting the lying plane of the feeding paths (p) of the wire rods with an inclination angle ( 3 ) greater than 5° and smaller than 85°.

TECHNICAL FIELD

The present invention relates to a wire-rods and the like hot-rolling machine.

More in detail, the present invention relates to a machine for producing hot-rolled rods for reinforced concrete. Use to which the following description will explicitly refer without this implying any loss of generality.

BACKGROUND ART

As known, reinforced concrete rods are obtained by subjecting a steel wire rod with an approximately circular section to a hot-rolling process which gradually reduces the nominal section of the wire rod.

The hot-rolling lines which are used to carry out this particular metallurgical process usually consist of a suitable number of roller-provided rolling units, which are arranged in sequence one after the other along the feeding path of the wire rod, so that each roller-provided rolling unit can slightly reduce the nominal section of the high-temperature steel wire rod while it is fed along the rolling line.

At present, each roller-provided rolling unit of the hot-rolling line is a completely separate machine, independent from the others, and usually consists of a rolling mill stand, which is provided with two opposite, counter-rotating rolling mills which are arranged one beside the other, locally substantially parallel and tangent to each other, so as to form/define a groove or neck therebetween, through which the wire rod to be hot-rolled is forced; and of an electric motor which is mechanically coupled to both rolling mills by means of a big reduction gearbox, so as to rotate the two rolling mills about respective longitudinal reference axes.

Obviously, the distance between the rotating axes of the two rolling mills gradually decreases along the feeding path of the wire rod, so that each pair of rolling mills can deform and stretch the wire rod thus slightly reducing the nominal section thereof.

For optimal rolling of the wire rod, the wire rod must be squeezed/deformed along a necking directrix which, while remaining on a reference plane orthogonal to the feeding direction of the wire rod, varies its angular orientation with respect to the body of the wire rod as the wire rod moves forward along the rolling line, whereby the rotation axes of the rolling mills of the various rolling units are usually arranged alternatively in horizontal and vertical position (or in all cases turned by 90°) so as to squeeze/deform the wire rod along alternatively orthogonal necking directrixes.

This constructional trick may also be used when the hot-rolling line is structured to hot-roll in parallel, i.e. at the same time, two wire rods that move forward in the line one beside the other. In this case, the two rolling mills of each roller-provided rolling unit, being they arranged with the rotation axes in vertical or horizontal position, are shaped/structured so as to form/define two separate rolling grooves or throttling therebetween, each of which is adapted to be engaged by a respective wire rod to be hot-rolled, and at least one of the two wire rods is fed in the hot-rolling line following an helical path which allows the wire rod to engage, in sequence, one of the two rolling grooves or throttling of each pair of rolling mills.

Unfortunately, this constructional trick cannot be used when the feeding speed of the wire rod is faster than 30-40 meters per second: experimental tests have indeed indicated that, if the feeding speed of the wire rod is greater than 30-40 meters per second, the wire rod which follows the helical path tends to jam in the hot-rolling line, thus halting the operation of the plant.

Given the impossibility of rolling in parallel two wire rods which are fed at a speed greater than 30-40 meters per second, manufacturers of hot-rolling plan for reinforced-concrete rods have thought to increase the hourly production rate of their plant by making hot-rolling lines in which the wire rod which is fed to the rolling line inlet, is longitudinally cut/split to obtain two wire rods of smaller section, which then continue along two separate, distinct branches of the rolling line, each of which consists of a series of roller-provided rolling units operating as independent, single-rod rolling lines.

Thank to this solution, the hourly production rate of the hot-rolling line can be doubled while keeping the wire rod speed in the range of about 100-120 meters per second, threshold above which the hot-rolling procedure becomes technically impractical.

Obviously, the longitudinal splitting of the wire rod, with consequent bifurcation of the hot-rolling line, may be repeated several times to considerably increase the hourly production rate of the hot-rolling line.

While ensuring a considerable increase of the hourly production rate, the tree-like structure of the hot-rolling line causes a considerable increase in the number of machines involved in rod production, resulting in higher running costs.

Simply bifurcating the hot-rolling line, indeed practically results in doubling the number of roller-provided rolling units, with consequent doubling of the extension of the shed where the rolling line is housed, and of the amount of spare parts which must be kept readily available for routine and supplementary maintenance of the rolling line.

DISCLOSURE OF INVENTION

Aim of the present invention is to realize roller-provided rolling units which are free from the above-mentioned problems, and which are able to minimize the space increase deriving from bifurcating a hot-rolling line.

In compliance with these aims, according to the present invention there is provided a wire-rods and the like hot-rolling machine as specified in claim 1 and preferably, though not necessarily, in any one of the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which show a non-limitative embodiment thereof, in which:

FIG. 1 is a perspective view of a wire-rods and the like hot-rolling machine for realized according to the teachings of the present invention, with parts removed for clarity;

FIG. 2 is a plan view of the machine shown in FIG. 1, with parts removed for clarity;

FIG. 3 is a front view of the machine shown in FIG. 2, with parts removed for clarity;

FIG. 4 is a section view of some components of the machine shown in FIG. 3, with parts removed for clarity; whereas

FIG. 5 is a front view of a second embodiment of the wire-rods and the like hot-rolling machine shown in the figures above, again with parts in section and parts removed for clarity.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIGS. 1, 2 and 3, reference numeral 1 indicates as a whole a machine for the hot-rolling in parallel and at high temperature of two metal wire rods b or similar semi-finished products, which machine is particularly advantageously used for producing rods for reinforced concrete.

More in detail, machine 1 is structured to hot-roll in parallel two metal wire rods b which are fed in the machine one beside the other, following respective feeding paths p which are locally substantially rectilinear and parallel to each other.

In other words, the feeding paths p of the two wire rods b lie on the same lying plane G, and are arranged at a predetermined distance d from each other preferably, though not necessarily, ranging from 0.3 to 3 meters.

In the example shown, in particular, the feeding paths p of the two wire rods b preferably, though not necessarily, develops in horizontal direction, while the lying plane G is inclined with respect to the vertical by an angle α preferably ranging from 30° to 60°, and preferably, though not necessarily, equal to about 45°.

Machine 1 essentially consists of a series of roller-provided rolling units or mill stands 2 which are arranged in sequence one after the other, aligned along the feeding paths p of both wire rods b, so that each roller-provided rolling unit 2 may plastically deform both high-temperature metal wire rods b that move forward each along a corresponding feeding path p, thus slightly reducing their nominal section.

With reference to FIGS. 1, 2 and 3, each rolling mill stand or unit 2 comprises two rolling-mills assemblies 3 which are arranged one beside the other, substantially coplanar to the same reference plane T locally substantially perpendicular to the feeding paths p of the two wire rods b (i.e. perpendicular to the longitudinal axis of the wire rod b and to the feeding direction of the wire rod), and are oriented on the reference plane T so that each rolling-mills assembly 3 is positioned on the feeding path p of a respective wire rod b.

More in detail, each rolling-mills assembly 3 is provided with a pair of reciprocally opposite, counter-rotating rolling mills 4, which are substantially circular, and are fixed in axially rotating manner to a rigid supporting structure one beside the other, so that their respective rotation axes R are locally substantially parallel to each other; and with a cascade of gears, which is structured so as to simultaneously drive into rotation the two rolling mills 4 about the respective rotation axes R at a substantially equal peripheral speed. Furthermore, the two rolling mills 4 are dimensioned so as to be locally substantially tangent to one another, while the peripheral surfaces of the two rolling mills 4 are profiled/structured so as to form/define a rolling groove or throttling 4 a therebetween, through which the wire rod to be hot-rolled is forced.

With reference to FIG. 1, the wire-rods and the like hot-rolling machine 1 furthermore comprises at least one drive unit 5 preferably, though not necessarily, of electric or hydraulic type, which is structured so as to be mechanically connected to the cascade of gears of least one of the two rolling-mills assemblies 3 of at least one of the rolling units 2, so as to simultaneously rotate the two rolling mills 4 of the aforesaid rolling-mills assembly 3.

In the example shown, in particular, the wire-rods and the like hot-rolling machine 1 is preferably provided with a single drive unit 5, which is structured to be mechanically connected to the gear cascades of both rolling-mills assemblies 3 of each rolling unit 2, in order to simultaneously drive into rotation the rolling mills 4 of all the roller-provided rolling units 2.

More in detail, in the example shown, the cascades of gears of the two rolling-mills assemblies 3 of each rolling unit 2 are preferably, though not necessarily, connected in cascade to the gear cascades of the two rolling-mills assemblies 3 of the immediately adjacent rolling units 2, and the drive unit 5 is structured so as to be mechanically connected to the gear cascades of the two rolling-mills assemblies 3 of a single rolling unit 2.

With reference to FIGS. 2 and 3, each of the two rolling-mills assemblies 3 of the same rolling unit 2 is further arranged on the reference plane T of the rolling unit 2, so that the rotation axes R of its rolling mills 4 lie on an plane substantially locally coinciding with, or however substantially parallel to, the reference plane T of the rolling unit 2 (the reference plane T is parallel to the sheet plane in FIG. 3), and so that the rolling groove or throttling 4 a thereof is arranged on the lying plane G of the feeding paths p of the wire rods, along the feeding path p of a respective wire rod b.

In addition to the above, the two rolling-mills assemblies 3 are further arranged on the reference plane

T of the rolling unit 2, so that the rotation axes R of the rolling mills 4 of the first rolling-mills assembly 3 are locally substantially parallel and preferably also coplanar to the rotation axes R of the rolling mills 4 of the second rolling-mills assembly 3, while intersecting the lying plane G of the feeding paths p of the two wire rods b with an inclination angle β greater than 5° and smaller than 85°.

In other words, with particular reference to FIG. 3, each rolling-mills assembly 3 is provided with a longitudinal reference axis L which lies on or is however parallel to the reference plane T of the rolling unit 2, and intersects the lying plane G of the feeding paths p of the wire rods with an inclination angle β greater than 5° and smaller than 85°; and the rotation axes R of the two rolling mills 4 are arranged parallel) and coplanar to the longitudinal axis L of the rolling assembly, in specular position on the opposite sides of the same longitudinal axis L. The rolling groove or throttling 4 a of the rolling-mills assembly 3 is instead positioned exactly on the longitudinal axis L of the rolling-mills assembly 3.

In the example shown, in particular, the two rolling-mills assemblies 3 of the same rolling unit 2 are preferably oriented so that the respective reference longitudinal axes L, and therefore the rotation axes R of the respective rolling mills 4, either lie on or are however parallel to the reference plane T, are locally parallel to each other and are finally inclined with the respect to the lying plane G by an angle β preferably, though not necessarily, equal to 45°, and in all cases preferably ranging from 30° to 60°.

With reference to FIGS. 1, 2, 3 and 4, in the example shown, in particular, the wire-rods or the like hot-rolling machine 1 is preferably, though not necessarily, provided with a horizontal, supporting crossbar 7 which extends under the lying plane G of the wire-rods feeding paths p, in a direction locally substantially parallel to the wire-rods feeding paths p, and the rolling-mills assemblies 3 which form the various rolling units 2 are fixed onto the supporting crossbar 7 in pairs one beside the other with the longitudinal reference axes L alternatively in horizontal and vertical position, so as to intersect the lying plane G of the wire-rods feeding paths p with an inclination angle β ranging from 30° to 60° and preferably, though not necessarily, equal to 45°.

More in detail, with reference to FIGS. 1 and 3, the second rolling-mills assembly 3 of a rolling unit 2 is arranged by the side of the first rolling-mills assembly 3 of the same rolling unit 2, but is moved/shifted either forwards or backwards with respect to the first rolling-mills assembly 3 in a direction locally substantially parallel to the longitudinal reference axes L of the two rolling-mills assemblies 3 (and thus also parallel to the rotation axes R of the rolling mills 4), by a length l in order to arrange the rolling grooves or throttling 4 a of both rolling-mills assemblies 3 on the lying plane G of the feeding paths p of the two wire rods b, each at the feeding path p of a respective wire rod b to be hot-rolled.

With reference to FIGS. 3 and 4, in particular, the two rolling-mills assemblies 3 of each rolling unit 2 are fixed to the supporting crossbar 7 one beside the other, so that the distance or axes-distance w between the longitudinal axes L of the two rolling-mills assemblies 3 is shorter than the distance d between the two wire rods b, or rather between the two feeding paths p of the wire rods, and satisfies the following mathematical equation:

w=d·sen(β);

where d is the distance between the two feeding paths p of the wire rods, and β is the inclination angle of the rotation axes R of the rolling mills 4 of the rolling unit 2 with respect to the lying plane G of the feeding paths p of the two wire rods b.

Moreover, the two rolling-mills assemblies 3 of each rolling unit 2 are fixed to the supporting crossbar 7 one beside the other, so that the two rolling mills 4 of the second rolling-mills assembly 3 are moved/shifted either forwards or backwards with respect to the two rolling mills 4 of the first rolling-mills assembly 3 by a length l in order to arrange the rolling grooves or throttling 4 a of both rolling-mills assemblies 3 on the lying plane G of the feeding paths p of the wire rods, each at the feeding path p of a respective wire rod b to be hot-rolled.

More in detail, the two rolling-mills assemblies 3 of the rolling unit 2 are arranged so that the distance or axes-distance w between the longitudinal axes L of the two rolling-mills assemblies 3, and the longitudinal offset value l of the two rolling mills 4 of the second rolling-mills assembly 3 with respect to the two rolling mills 4 of the first rolling-mills assembly 3, satisfy the following mathematical equations:

l=d·cos(β);

w=d·sen(β);

where d is the distance between the two wire rods b or rather between the two feeding paths p of the wire rods, and β is the inclination angle of the rotation axes R of the rolling mills 4 of the rolling unit 2 with respect to the lying plane G of the feeding paths p of the two wire rods b.

With reference to FIG. 3, in the example shown, in particular, the two rolling-mills assemblies 3 of each rolling unit 2 are fixed to the supporting crossbar 7 one beside the other, so that the rotation axes R of the rolling mills 4 are inclined with respect to the lying plane G of the feeding paths p of the wire rods by an angle β preferably of about 45°. Therefore, the distance or axes-distance w between the longitudinal reference axes L of the two rolling-mills assemblies 3, and the longitudinal offset l between the two rolling mills 4 of the first and second rolling-mills assemblies of the rolling unit 2 must satisfy the following mathematical equations:

$ = {d \cdot \frac{1}{\sqrt{2}}}$ $w = {d \cdot \frac{1}{\sqrt{2}}}$

where d is the distance between the two wire rods b, or rather between the two feeding paths p of the wire rods.

With reference to FIGS. 1, 2, and 3, the two rolling-mills assemblies 3 of a rolling unit 2 are additionally located on the reference plane T of their rolling unit 2 in a specular position and offset with respect to the two rolling-mills assemblies 3 of the immediately adjacent rolling unit(s) 2, so as to arrange the corresponding longitudinal reference axes L according to a substantially W-shaped, crossed arrangement in which the vertexes of the two Vs are each arranged at the feeding path p of a respective wire rod b to be hot-rolled.

In other words, the two rolling-mills assemblies 3 which belong to two adjacent rolling units 2 and which intersect the same wire-rod feeding path p the one after the other, are arranged on the corresponding reference planes T with the longitudinal axes L arranged in a specular position and reciprocally offset to one another, so as to cross each other at the feeding path p of the wire rod, i.e. so as to form a V whose vertex is located on the feeding path p of the wire rod.

Thereby, the rotation axes R of the two pairs of rolling mills 4 cross each other at the feeding path p of the wire rod.

With reference to FIGS. 1, 2, 3 and 4, in the example shown, in particular, the rolling-mills assemblies 3 forming the various rolling mill stands or units 2 preferably, though not necessarily, consist of a series of elementary sectional modules 10 with a mutually equivalent structure, each of which comprises: a preferably substantially parallelepiped-shaped, rigid box-like casing 11 which is arranged on the reference plane T of the rolling unit 2 so that the longitudinal axis thereof coincides with the longitudinal reference axis L of the rolling-mills assembly 3, and so that the upper end 11 a thereof directly faces the lying plane G of the feeding paths P of the wire rods; and a pair of rotating supporting shafts 12 which are inserted in axially rotating manner into the upper end 11 a of the rigid box-like casing 11 one beside the other, and which cantileverly jut out from the same upper end 11 a of the casing towards the lying plane G while remaining coaxial to respective rotation axes R′ locally parallel to each other and to the longitudinal axis L of the rigid box-like casing 11.

The two supporting shafts 12 are furthermore inserted into the rigid box-like casing 11 so that the lying plane of the two rotation axes R′ substantially coincides with, or is however parallel to, the reference plane T of the rolling unit 2, and that the rotation axis R′ of each supporting shaft 12 intersects the lying plane G of the two feeding paths p of the wire rods with an inclination angle equal to the inclination angle of the rotation axes of the rolling mills 4 with respect to the same lying plane G.

More in detail, with reference to FIG. 4, in the example shown, each supporting shaft 12 of the elementary sectional module 10 is preferably, though not necessarily, fitted in an axially rotating manner into a respective intermediate supporting bushing or bush 13 which is provided with a longitudinal, eccentric pass-through hole 13 a, and is in turn inserted in an axially rotating manner into the body of the rigid box-like casing 11, so as to freely rotate about a reference axis locally parallel to the longitudinal axis L of the rigid box-like casing 11 and at same time offset with respect to the rotation axis R′ of the supporting shaft 12.

The elementary sectional module 10 is furthermore provided with a bushing moving mechanism (not shown), which is structured so as to vary, on command, the angular position of both supporting bushings or bushes 13 in a synchronized manner, so as to vary/adjust the distance between the rotation axes R′ of the two supporting shafts 12.

With reference to FIGS. 1, 2, 3 and 4, each elementary sectional module 10 furthermore comprises a driving shaft 14 which extends coaxially to a reference axis A locally perpendicular to the longitudinal axis L of the rigid box-like casing 11 and to the lying plane of the supporting shafts 12, and is inserted in a pass-through and axially rotating manner through the rigid box-like casing 11, next to the lower end 7 b of the same casing; and a series of toothed wheels and idle shafts 15, which are located within the rigid box-like casing 11, and are structured so at to transmit the rotary motion of the driving shaft 14 to the two supporting shafts 12 with a predetermined angular speed reduction/increase coefficient.

Obviously, the reduction ratio of the gear cascade which connects the driving shaft 14 to the two supporting shafts 12 varies according to the position of the rolling unit 3 along the rolling line.

In addition to the above, with reference to FIGS. 1 and 2, the various elementary sectional modules 10 are preferably fixed to the supporting crossbar 7 aligned one after the other so as to form four rows parallel to the feeding paths p of the wire rods, so to align the driving shafts 14 along four reference lines parallel to one another and to the two feeding paths p of the wire rods. This configuration allows to mechanically connect the driving shafts 14 of the various elementary sectional modules 10 in cascade to one another, preferably by means of simple joint sleeves (not shown).

Finally, with reference to FIG. 1, the drive unit is instead preferably arranged at the end of the supporting crossbar 7, so as to be aligned with the four rows of driving shafts 14, and preferably, though not necessarily, consists of a high-power, electric motor 16 and of a big reduction gearbox 17 which connects the drive shaft of the electric motor 16 to the distal end of the four feeding shafts 14 of the first rolling unit 2 of the supporting crossbar 7, i.e. the rolling unit 2 closer to drive unit 5.

General operation of the wire-rods hot-rolling machine 1 is easily inferable from the above description, and thus no further explanations are required.

The advantages deriving from the particular structure of the single rolling mill stands or units 2 are considerable.

Firstly, by virtue of the particular structure and arrangement of the rolling mill stands or units 2, the wire-rods and the like hot-rolling machine 1 is able to hot-roll two or more wire rods b in parallel by feeding the wire rods b along respective feeding paths p which are locally perfectly rectilinear and parallel to one another. This geometry allows to take the feeding speed of each wire rod b to the maximum value currently allowed for hot-rolling processes, i.e. up to about 100-120 meters per second.

The particular space arrangement of the rolling-mills assemblies 3 forming the various rolling mill stands or units 2 further allows the rolling mill stands 2 to be connected in cascade to one another, so as to use a single drive unit 5 to simultaneously drive into rotation the rolling mills 4 of all the rolling units 2, thus significantly reducing the overall dimensions of the machine.

Furthermore, as each rolling unit 2 consists of two completely separate and independent rolling-mills assemblies 3, the transportation on site and the subsequent assembly of the wire-rods and the like hot-rolling machine 1 is greatly facilitated.

Finally, as each rolling unit 2 consists only of to elementary sectional modules 10 which are substantially identical in structure, the design of the whole wire-rods and the like hot-rolling machine 1 and the construction of single component parts are greatly simplified.

It is finally apparent that changes and variations can be made to the wire-rods and the like hot-rolling machine 1 described above without departing from the scope of the present invention.

For example, with reference to FIG. 3, in a more sophisticated embodiment, the wire-rods and the like hot-rolling machine 1 may be structured so as to hot-roll three or more metal wire rods b in parallel, which are fed one beside the other following respective feeding paths p which are locally substantially rectilinear, parallel and equally spaced apart, all lying on the same lying plane G which is preferably, though not necessarily horizontal.

More in detail, each rolling mill stand or unit 2 of machine 1 may consist of three or more (three in the example shown) rolling-mills assemblies 3 preferably, though not necessarily, substantially identical to one another, which are arranged on the reference plane T of the roller-provided rolling unit 2 so to be parallel to and adjacent to the other, so as to place the respective rolling grooves or throttling 4 a on the lying plane G of the wire-rods feeding paths p, each at the feeding path p of a respective wire rod b, and so that the rotation axes R of the rolling mills 4 are locally substantially parallel to one another and to the reference plane T of the roller-provided rolling unit 3, while intersecting the lying plane G of the wire-rods feeding paths p with an inclination β preferably, though not necessarily, equal to 45°, and in any case preferably ranging from 30° to 60°.

In addition to the above description, the three or more rolling-mills assemblies 3 are furthermore preferably arranged on the reference plane T of the rolling unit 2 so that the rotation axes R of the rolling mills 4 are also all locally substantially coplanar to one another.

In the example shown, in particular, the three rolling-mills assemblies 3 are preferably positioned on the reference plane T of the roller-provided rolling unit 3 one against the other.

Obviously, also in this case the three or more rolling-mills assemblies 3 of a rolling unit 2 are located on the reference plane T of their rolling unit 2 in a specular position and offset with respect to the three or more rolling-mills assemblies 3 of the immediately adjacent rolling unit(s) 2, so as to arrange the longitudinal reference axes L according to a substantially W-shaped, crossed arrangement, in which the vertexes of the two Vs are each arranged at the feeding path p of a respective wire rod b to be hot-rolled.

In other words, the two rolling-mills assemblies 3 which belong to two adjacent rolling units 2 and which intersect the same feeding path p of the wire rod one after the other, are positioned on corresponding reference planes T with the longitudinal axes L arranged in a symmetric position and reciprocally offset so as to cross each other along the feeding path of the wire rod p, i.e. so as to form a V, the vertex of which is on the feeding path p of the wire rod.

Finally, also in this case the rolling-mills assemblies 3 may consist of a series of elementary sectional modules 10 which are preferably fixed to the supporting crossbar 7 and aligned one after the other so as to form a double number of rows of elementary section modules 10 as compared to the number of feeding paths p of the wire rods. 

1. Wire-rod and the like hot-rolling machine adapted to hot roll in parallel two or more which are fed one beside the other along respective feeding paths, and which comprises a plurality of roller-provided rolling units which are arranged one after the other along the wire-rods feeding paths, so that each roller-provided rolling unit can plastically deform all wire-rods while these are fed along the respective feeding paths; the wire-rod and the like hot-rolling machine being characterized in that said feeding paths are locally substantially rectilinear and parallel to one another; in that at least a first roller-provided rolling unit comprises a plurality of rolling-mills assemblies, each of which is provided with a pair of opposite and counter-rotating rolling mills which are arranged parallel and adjacent each other, so as to define a rolling groove or throttling through which the wire-rod to be hot-rolled is forced; and in that said rolling-mills assemblies are arranged one beside the other, substantially coplanar to a corresponding reference plane locally substantially perpendicular to the feeding paths of the wire-rods, so as to arrange the respective rolling groove or throttling on the lying plane of the feeding paths of the wire-rods, each at the feeding path of a respective wire-rod, and are oriented so that the rotation axes of the rolling mills of the various rolling-mills assemblies are locally substantially parallel to one another and simultaneously intersect the lying plane of the wire-rods feeding paths with an inclination angle greater than 5° and smaller than 85°.
 2. Wire-rod and the like hot-rolling machine according to claim 1, characterised in that the rolling-mills assemblies are arranged on the reference plane so that the rotation axes of the rolling mills of the rolling-mills assemblies intersect the lying plane of the feeding paths of the wire-rods with an inclination angle in the range between 30° and 60°.
 3. Wire-rod and the like hot-rolling machine according to claim 2, characterised in that the rolling-mills assemblies are arranged on the corresponding reference plane so that the rotation axes of the rolling mills of the rolling-mills assemblies intersect the lying plane of the wire-rods feeding paths with an inclination angle of about 45°.
 4. Wire-rod and the like hot-rolling machine according to claim 1, characterised in that the rotation axes of all the pairs of rolling mills are locally parallel to the reference plane, and are substantially coplanar to one another.
 5. Wire-rod and the like hot-rolling machine according to claim 1, characterised in that also a second roller-provided rolling unit comprises a plurality of rolling-mills assemblies, each of which is provided with a pair of opposite and counter-rotating rolling mills which are positioned parallel and adjacent each other, so as to define a rolling groove or throttling through which the wire-rod to be hot-rolled is forced; and in that the rolling-mills assemblies of said second roller-provided rolling unit are arranged one beside the other, substantially coplanar to a corresponding reference plane locally substantially perpendicular to the wire-rods feeding paths, so as to arrange the respective rolling grooves or throttlings on the lying plane of the wire-rods feeding paths, each at the feeding paths of a respective wire-rod, and are oriented on said reference plane specularly with respect to the rolling-mills assemblies of the first roller-provided rolling unit.
 6. Wire-rod and the like hot-rolling machine according to claim 5, characterised in that each rolling-mills assembly is provided with a longitudinal reference axis which is parallel to the reference plane; in that the two rolling mills of each rolling-mills assembly are arranged in a specular position on opposite sides of said longitudinal axis; and in that the two rolling-mills assemblies which belong to two adjacent roller-provided rolling units and which intersect one after the other a same wire-rod feeding path, are arranged on the respective reference planes with the longitudinal axes arranged in a specular position reciprocally offset one with respect to another, so as to reciprocally cross on the wire-rod feeding path.
 7. Wire-rod and the like hot-rolling machine according to claim 1, characterised in that the wire-rods feeding paths are arranged at a distance one from the other ranging between 0.3 and 3 metres.
 8. Wire-rod and the like hot-rolling machine according to claim 1, characterised by comprising a supporting crossbar which extends below the lying plane of the wire-rods feeding paths in a direction locally substantially parallel to the wire-rod feeding path; and in that the rolling-mills assemblies which form the various roller-provided rolling units, are fixed on the supporting crossbar in pairs one beside the other.
 9. Wire-rod and the like hot-rolling machine according to claim 8, characterised in that the rolling-mills assemblies which form the various roller-provided rolling units are formed by a series of elementary sectional modules structurally identical to one another.
 10. Wire-rod and the like hot-rolling machine according to claim 9, characterised in that the elementary sectional modular elements are fixed on the supporting crossbar aligned one after another, so as to form a plurality of rows of elementary sectional modules parallel to the wire-rods feeding paths. 